general map service performance

I want to make an application using Flex which consumes REST Service... Which one is better in term of performance :- Make A map service with A layer which consisted of many States (the MXD has 1 layer for all States) or- Make A map service with MANY State layers (the MXD has n-state layers) or- Make many State map services

And.., out of these three map services, which one consumes the most server's resources ?

Since you've posted this in the Geodatabase forum and not over in a Server one, I'll point out that you could design a database to make any of these options both much better or much worse than the others, much the way any of those techniques could be used in the right context. - V